Use of imidazolinyl benzoates as herbicidal agents

ABSTRACT

The invention relates to novel imidazolinyl benzoic acids, esters and salts, a method for the preparation of the compounds and methods for controlling undesirable plant species therewith.

This is a division, of application Ser. No. 914,244, filed June 9, 1978, now U.S. Pat. No. 4,188,487 which is a Continuation-in-Part of Ser. No. 822,458 Filed Aug. 8, 1977, now abandoned.

The invention is imidazolinyl benzoic acids, esters and salts represented by formula (I): ##STR1## wherein X is hydrogen, alkyl C₁ -C₃, halogen or nitro; R₁ is alkyl C₁ -C₄ ; R₂ is alkyl C₁ -C₆, cycloalkyl C₃ -C₆, alkenyl C₂ -C₄, phenyl, halophenyl or benzyl or when R₁ and R₂ are taken together with the carbon to which they are attached they may represent cycloalkyl C₃ -C₆ optionally substituted with methyl; R₃ is hydrogen, alkyl C₁ -C₁₂ optionally substituted with one C₁ -C₃ alkoxy group or one C₃ -C₆ cycloalkyl group or one phenyl group or one furyl group or with one to three halogen substituent(s) preferably chlorine, alkenyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s) preferably chlorine, alkynyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s) preferably chlorine, benzyl, cyclohexenylmethyl, ethynylcyclohexyl, ethynylalkyl, pentadienyl or cycloalkyl C₃ -C₆ optionally substituted with one or two C₁ -C₃ alkyl group(s); or a salt forming cation of alkali metals, ammonium and aliphatic ammonium; and when R₁ and R₂ are not the same the optical isomers and the isomeric mixtures thereof; and except when R₃ is a salt-forming cation, the acid addition salts thereof.

The invention also relates to a method for controlling undesirable plant species with imidazolinyl benzoates comprising applying to the foliage of the undesirable plant species or to soil containing seeds, seedlings, or propagating organs of the undesirable plant species, a herbicidally effective amount of an imidazolinyl benzoate compound depicted by formula I above.

The invention further relates to a method for the preparation of the formula I imidazolinyl benzoates.

Preferred compounds for use as herbidical agents are those represented by formula I above, wherein X is hydrogen, alkyl C₁ -C₃ or halogen; R₁ is alkyl C₁ -C₃ ; R₂ is alkyl C₁ -C₃ or cyclohexyl, and when R₁ and R₂ are taken together with the carbon to which they are attached they represent cyclohexyl or methylcyclohexyl; R₃ is hydrogen, alkyl C₁ -C₁₂ optionally substituted with one C₁ -C₃ alkoxy group or one C₃ -C₆ cycloalkyl group or one phenyl group or one furyl group or with one to three halogen substituent(s) preferably chlorine, alkenyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituents(s) preferably chlorine, alkynyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s) preferably chlorine, benzyl, cyclohexenylmethyl, ethynylcyclohexyl, ethynylalkyl, pentadienyl or cycloalkyl C₃ -C₆ optionally substituted with one or two C₁ -C₃ alkyl group(s); or a salt forming cation of alkali metals and ammonium; and when R₁ and R₂ are not the same the optical isomers and the isomeric mixtures thereof; and except when R₃ is a salt-forming cation, the acid addition salts thereof.

Still more preferred formula (I) compounds are those wherein R₁ is methyl; R₂ is isopropyl; and the compounds may be grouped as follows:

a. wherein X is hydrogen or chlorine; R₃ is hydrogen; the alkali metal and ammonium salts thereof; the optical isomers thereof, and the isomeric mixtures thereof;

b. wherein X is hydrogen, methyl or chlorine; R₃ is alkyl C₁ -C₁₂ optionally substituted with one C₁ -C₃ alkoxy group or one C₃ -C₆ cycloalkyl group or one phenyl group or one furyl group or with one to three halogen substituent(s) preferably chlorine; the optical isomers thereof, and the isomeric mixtures thereof, and the acid addition salts thereof;

c. wherein X is hydrogen, methyl or chlorine; R₃ is alkenyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s) preferably chlorine; the optical isomers thereof, and the isomeric mixtures thereof, and the acid addition salts thereof;

d. wherein X is hydrogen, methyl or chlorine; R₃ is alkynyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s) preferably chlorine; the optical isomers thereof, and the isomeric mixtures thereof, and the acid addition salts thereof.

In accordance with this invention, formula I imidazolinyl benzoates wherein R₃ is not H can be prepared by reacting an imidazoisoindoledione represented by formula II with an appropriate alkali metal alkoxide. The reaction is preferably conducted under a blanket of inert gas at a temperature between 20° C. and 50° C. Generally, an alkali metal or alkali metal hydride is mixed with an appropriate alcohol and the mixture then admixed with the imidazoisoindoledione II.

Among the inert gases which may be used to blanket these reactions are nitrogen, argon and helium; but nitrogen is preferred.

Alkali metals and alkali metal hydrides which may be used include sodium, sodium hydride, potassium, potassium hydride, lithium and lithium hydride.

These reactions may be graphically illustrated as follows: ##STR2## wherein X, R₁, R₂ and R₃ are as described above.

In these reactions, the alcohol functions as both reactant and solvent. As such, a secondary solvent is not required; however, when an expensive alcohol is used in the reaction and/or a large excess of alcohol would normally be required to provide optimum reaction conditions, it may be desirable to add a less expensive secondary solvent such as dioxane, tetrahydrofuran or other non-protic solvent, to the reaction mixture. The amount of non-protic solvent added to the reaction mixture may be widely varied in this use; however, it generally will not exceed fourfold the amount of alcohol used. Thus, the ratio of secondary solvent to alcohol, which may be employed in the process of the present invention, is from 0.0:1 to 4.0:1.

Formula I compounds, wherein R₃ is hydrogen are prepared by reacting a formula II imidazoisoindoledione with an excess of hydrochloric acid in the presence of a water-miscible solvent such as tetrahydrofuran or dioxane. This reaction yields the formula IV lactone hydrochloride which, when treated with one equivalent of base such as sodium hydroxide, potassium hydroxide or sodium carbonate, yields the corresponding acid. This reaction can be illustrated as follows: ##STR3##

The thus-formed imidazolinyl acid can then be converted to the corresponding alkali metal, ammonium or aliphatic ammonium salt.

Where the alkali metal salt is desired, the acid is treated with a concentrated aqueous solution of the alkali metal hydroxide, followed by removal of the water, preferably through azeotropic distillation with an organic solvent such as dioxane.

The ammonium or aliphatic ammonium salts prepared in similar fashion excepting that the formula I acid is partially dissolved in a lower alcohol such as methanol, ethanol, isopropanol, or the like, and the thus-formed solution treated with ammonia or the appropriate aliphatic amine. Thereafter, the reaction mixture is concentrated and the remaining solid treated with hexane and then dried to recover the ammonium or aliphatic ammonium formula I salt.

The term, "aliphatic ammonium," means an aliphatic ammonium group of monoalkylammonium, dialkylammonium, trialkylammonium, monoalkenylammonium, dialkenylammonium, trialkenylammonium, monoalkynylammonium, dialkynylammonium, trialkynylammonium, monoalkanolammonium, dialkanolammonium, or trialkanolammonium, and the aliphatic ammonium group containing from 1 to 18 carbon atoms.

The aliphatic ammonium salts of the compounds of the invention are prepared from organic amines having a molecular weight below about 300. These amines include methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, isobutylamine, sec-butylamine, n-amylamine, iso-amylamine, hexylamine, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, octadecylamine, methylethylamine, methylisopropylamine, methylhexylamine, methylnonylamine, methylpentadecylamine, methyloctadecylamine, ethylbutylamine, ethylheptylamine, ethyloctylamine, hexylheptylamine, hexyloctylamine, dimethylamine, diethylamine, di-n-propylamine, diisopropylamine, di-n-amylamine, diisoamylamine, dihexylamine, diheptylamine, dioctylamine, trimethylamine, triethylamine, tri-n-propylamine, triisopropylamine, tri-n-butylamine, triisobutylamine, tri-sec-butylamine, tri-n-amylamine, ethanolamine, n-propanolamine, isopropanolamine, diethanolamine, N,N-diethylethanolamine, N-ethylpropanolamine, N-butylethanolamine, allylamine, n-butenyl-2-amine, n-pentenyl-2-amine, 2,3-dimethylbutenyl-2-amine, di-butenyl-2-amine, n-hexenyl-2-amine and propylenediamine.

The compounds represented by formula (I) above may be mixtures of two position isomers when X is other than hydrogen, since the intermediate imidazoisoindolediones of formula (II) are also mixtures of isomers when X is not hydrogen. As shown below, the compounds of formula (II) may be prepared from the corresponding phthalimidocarboxamide precursors by cyclizing same, and that cyclization occurs at either imide carbonyl group giving rise to an isomeric mixture when X is other than hydrogen: ##STR4## wherein R₁, R₂ and X are defined above, excepting that X cannot be hydrogen.

It should also be understood that the imidazolinyl benzoates represented by formula I above, may be tautomeric. While, for convenience, they are depicted by a single structure identified as formula I, they may exist in either of the isomeric forms illustrated as follows: ##STR5## wherein X, R₁, R₂ and R₃ are as described. As such, both isomeric forms of the imidazolinyl benzoates are meant to be included under the formula I definition.

These compounds are amphoteric. They will dissolve in both acidic and basic aqueous solutions and when treated with strong acids, particularly strong mineral acids such as hydrochloric acid, sulfuric acid or hydrobromic acid, will form the acid addition salts of the imidazolinyl benzoates I.

It should also be understood than when R₁ and R₂ represent different groups on the imidazolinyl benzoates, depicted by formula I, the carbon atom to which they are attached is an asymmetric carbon atom. Therefore, the products (as well as their intermediates) exist in d- and l- forms as well as dl- forms.

Preparation of the d- or the l- form is thus readily obtained by reacting the appropriate optically active d- or l-imidazoisoindoledione II with the appropriate alcohol III to obtain the corresponding d- or l-imidazolinyl benzoate I.

The formula II imidazoisoindolediones II which are used as intermediates for the preparation of the imidazolinyl benzoates of this invention are described in my U.S. Pat. No. 4,017,510, issued Apr. 12, 1977.

The compounds of this invention are highly effective herbicidal agents useful for the control of both monocolyledonous, sedge (cyperaceous) and dicotyledonous plants. They may be employed for the postemergence control of undesirable plant species by applying a herbicidally effective amount thereof to the foliage of the plants, or they may be used for the preemergence control of the undesirable plants by applying a herbicidally effective amount of the active compound to soil containing seeds, seedlings or propagating organs, of the undesirable plants. Since the imidazolinyl benzoates (I) of the present invention exhibit very limited solubility in water, they are generally formulated as wettable powders, emulsifiable concentrates, or flowable liquids which are usually dispersed in water or other inexpensive liquid diluent for application as a liquid spray. The compounds of the invention may also be prepared as granular formulations containing, generally, about 10% to 15% by weight of toxicant.

Typically, a wettable powder can be prepared by grinding together about 25% to 80% by weight of the imidazolinyl benzoate, about 2% to 5% by weight of a surfactant such as sodium N-methyl-N-oleoyl taurate, alkyl phenoxy polyoxyethylene ethanol, or sodium alkyl naphthalene sulfonate, 5% to 10% by weight of a dispersing agent such as a highly purified sodium lignosulfonate and 25% to 63% by weight of a finely divided carrier such as kaolin, attapulgite, diatomaceous earth, or the like.

A typical formulation prepared in accordance with the above description is as follows:

50% by weight of 2-propynyl-o-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl) benzoate, 3% by weight of sodium N-methyl-N-oleoyl taurate, 10% by weight of sodium lignosulfonate, and 37% by weight of kaolin.

Flowable liquid formulations can be prepared by grinding together about 40% to 60% by weight of the formula I imidazolinyl benzoate, 2% to 3% by weight of the sodium salt of condensed naphthalene sulfonic acid, 2% to 3% by weight of a gelling clay, 2% by weight of propylene glycol, and from 54% to 32% by weight of water.

A typical granular formulation can be prepared by dissolving or dispersing the active compound in a solvent and applying the toxicant to a sorptive or non-sorptive carrier such as attapulgite, corn cob grits, pumice, talc, or the like.

As indicated above, the imidazolinyl compounds, depicted by formula I, are effective preemergence herbicides. They are highly effective for the control of broadleaf weeds and grass plants when applied at a rate of from about 0.07 kg per hectare to 11.2 kg per hectare to soil containing seeds, seedlings or propagating organs of the broadleaf weeds, sedges, or grass plants.

The compounds of the invention are also effective for the control of broadleaf weeds, sedges, and grass plants when applied at the rate of from about 0.28 kg per hectare to 11.2 kg per hectate to the foilage of the plants.

While the compounds of this invention are very effective for controlling a wide variety of plant species, they are unique among herbicides in their ability to control certain cyperaceous plants, particularly sedges, at relatively low rates of application. In practice, the formula I compounds have been found to be most effective as sedge control agents when applied as a preemergence application at rates of from 0.14 kg per hectare to 11.2 kg per hectare. It is, of course, recognized that higher rates of application of the formula I compounds can be used for sedge and other perennial plant control when infestations of the cyperacae or perennial plants are especially heavy. Under such conditions, the formula I imidazolinyl benzoates may be applied, preemergence or postemergence, at rates as high as 25 kg per hectare.

Among the cyperacae which can be controlled with the imidazolinyl benzoates of this invention are purple nutsedge (Cyperus rotundus L.), yellow nutsedge (Cyperus esulentus L.), false nutsedge (Cyperus strigosus) and the flat sedges, umbrella plants and kyllinga.

This invention is further illustrated by the following examples:

EXAMPLE 1 Preparation of 2-Propynyl o-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoate.

To 12.5 ml of propargyl alcohol is added 0.1 g of a 50% suspension of sodium hydride in mineral oil. The addition is made under a blanket of nitrogen while the mixture is stirred and the temperature thereof maintained at from 20° C. to 25° C. by means of external cooling. The formation of the sodium salt of propargyl alcohol is complete in about 1 to 2 hours. To this solution is added 5.0 g of 3-isopropyl-3-methyl-5H-imidazo[2,1-a]isoindole-2(3H),5-dione and the mixture stirred at room temperature overnight under a blanket of nitrogen. Thin layer chromatography indicates incomplete reaction and an additional 50 mg of a 50% suspension of sodium hydride in oil is added to the reaction mixture. After stirring overnight, the mixture is cooled to 5° C. and 0.7 ml of 3 N hydrochloric acid is added. The mixture is then diluted with methylene chloride, washed with water and the organic phase dried and concentrated in vacuo. The crystalline residue is transferred to a filter funnel with hexane and air dried to give 6.02 g of 2-propynyl o-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoate, melting point 131°-144° C. Material from a similar reaction was recrystallized from acetone-hexane to give pure product melting point 145°-147° C.

EXAMPLE 2 Preparation of Formula I Imidazolinyl Benzoates.

The following imidazolinyl benzoates were prepared by essentially the same procedure as that described in Example 1, but substituting the appropriate alcohol for propargyl alcohol and the appropriate imidazoisoindoledione for 3-isopropyl-3-methyl-5H-imidazo[2,1-a]isoindole-2(3H),5-dione. Graphically, the reaction may be illustrated as follows:

    __________________________________________________________________________      ##STR6##                                                                      R.sub.1 R.sub.2 R.sub.3       X     Melting Point °C.                   __________________________________________________________________________     CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CH.sub.2 CH.sub.3                                                                   H     120-121.5 (dec.)                           CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 C.sub.6 H.sub.5                                                                     H     110-113 (dec.)                             CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     (CH.sub.2).sub.7 CH.sub.3                                                                    H     73-75 (dec.)                               CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     (CH.sub.2).sub.11 CH.sub.3                                                                   H     62.5-64.5 (dec.)                           CH.sub.3                                                                               CH(CH.sub. 3).sub.2                                                                    CH.sub.2 CHCH.sub.2                                                                          H     109-111.5 (dec.)                           CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.3      H     117-118                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C(CH.sub.3).sub.2 CHCH.sub.2                                                                 H     115.5-117.5                                CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C(CH.sub.3).sub.2 CCH                                                                        H     115-116                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3).sub.2                                                                           H     121-122.5                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C(CH.sub.3).sub.3                                                                            H     139.5-141                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CH.sub.3                                                                            H     123-124.5                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)CCH                                                                              H     97-104                                     CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 C(Cl)CH.sub.2                                                                       H     114-116                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CH.sub.2 CCH                                                                        H     127-128                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)CHCH.sub.2                                                                       H     94-98 (dec.)                               CH.sub.3                                                                               CH.sub.2 CH.sub.2 CH.sub.3                                                             C(CH.sub.3 ).sub.2 CHCH.sub.2                                                                H     103.5-107 (dec.)                           CH.sub.3                                                                                ##STR7##                                                                              C(CH.sub.3).sub.2 CHCH.sub.2                                                                 H     115-120 (dec.)                             (CH.sub.2).sub.5                                                                               C(CH.sub.3).sub.2 CHCH.sub.2                                                                 H     133.5-134.5 (dec.)                         CH(CH.sub.3)CH.sub.2 CH.sub.2 CH.sub.2 CH.sub.2                                                CH.sub.2 CCH  H     168-171 (dec.)                             CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)C(CH.sub.3)CH.sub.2                                                              H     85-94 (dec.)                               CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CHCHCH.sub.3                                                                        H     101-112 (dec.)                             CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 C(CH.sub.3)CH.sub.2                                                                 H     91-102 (dec.)                              CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CHC(CH.sub.3).sub.2                                                                 H     107-111                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR8##     H     100-106 (dec.)                             CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CHCH.sub.2).sub.2                                                                         H     78-87 (dec.)                                CH.sub.3                                                                              CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)CHCHCH.sub.3                                                                     H     89-107 (dec.)                              CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3).sub.2                                                                     CH.sub.3      H     146-147                                    (CH.sub.2).sub.5                                                                               CH.sub.3      H     164-165                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 C(CH.sub.3).sub.3                                                                   H     147-148                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.18 H.sub.37n                                                                           H     79-81.5                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CH.sub.2 OCH.sub.3                                                                  H     87.5-92.5                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR9##     H     122-125                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.6 H.sub.13n                                                                            H     84-86                                      CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR10##    H     87-89                                      CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5                                                           H     99-100                                     CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CHCHC.sub.6 H.sub.5                                                                  H     120-125                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      CH.sub.2CCC.sub.6 H.sub.5                                                                   H     134.5-138                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CCCH.sub.3                                                                           H     125-128                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR11##    H     95.98                                      CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CCC.sub.7 H.sub.15n                                                                  H     94-96.5                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2 CCl.sub.3                                                                           H     143-145                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C(C.sub.2 H.sub.5).sub.2 CHCH.sub.2                                                          H     111.5-115.5                                CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR12##    H     74-78                                      CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR13##    H     168-169                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR14##    4(5) CH.sub.3                                                                        128- 130                                   CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.3      4(5) CH.sub.3                                                                        143-151                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CCH   4(5) CH.sub.3                                                                        154-159                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR15##    H     153-157.5                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.2 H.sub.5                                                                              H     106-108                                            (+) isomer                                                             CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CCH   H     134-135                                            (-) isomer                                                             CH.sub.3                                                                               CH(CH.sub.3).sub.2 (+) isomer                                                           ##STR16##    H     120-122                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)CHCHCH.sub.3                                                                     4(5) CH.sub.3                                                                        95-111                                     CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.3      3(6) Cl                                                                              162-166                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CCH   3(6) Cl                                                                              164-166                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2C CCH.sub.2 OH                                                                       H     132-134                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR17##    3(6) Cl                                                                              154-160                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CH.sub.2                                                                             H     166-169                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)CHCHCH.sub.3                                                                     3(6) Cl                                                                              161-163                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.2 H.sub.5                                                                              3(6) NO.sub.2                                                                        156-157                                    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                        CH.sub.3      H     135-136                                    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                        CH.sub.2CCH   H     137-139                                    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                         ##STR18##    H     125-126                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR19##    H     107-114                                    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                        CH(CH.sub.3)CHCHCH.sub.3                                                                     H     119-121                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR20##    3(6) NO.sub.2                                                                        161-162                                    CH.sub.3                                                                               CH(CH.sub.3).sub. 2                                                                     ##STR21##    H     73-79                                      CH.sub.3                                                                               C.sub.2 H.sub.5                                                                         ##STR22##    H     127-128                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR23##    H     122-122.5                                  CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.2 H.sub.5                                                                              4(5) Cl                                                                              112-138                                    C.sub.2 H.sub.5                                                                        CH(CH.sub.3).sub.2                                                                     CH.sub.3      H     139-140                                    C.sub.2 H.sub.5                                                                        CH(CH.sub.3).sub.2                                                                     CH.sub. 2CCH  H     147-149                                    C.sub.2 H.sub.5                                                                        CH(CH.sub.3).sub.2                                                                      ##STR24##    H     134-135                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH.sub.2CCH   4(5) Cl                                                                              177-187                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3)CHCHCH.sub.3                                                                     4(5) Cl                                                                              oil                                        CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR25##    4(5) Cl                                                                              oil                                        CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR26##    H     oil                                        CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                      ##STR27##    4(5) Cl                                                                              oil                                        CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     H             4(5) Cl                                                                              177-179                                    CH.sub.3                                                                               C.sub.2 H.sub.5                                                                        H             H     195-197                                    C.sub.2 H.sub.5                                                                        CH(CH.sub.3).sub.2                                                                     H             H     179-180                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     H             3(6) Cl                                                                              154-156                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.2 H.sub.5                                                                              4(5) CH.sub.3                                    CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.3 H.sub.7n                                                                             4(5) CH.sub.3                                                                  (4 or 5)                                         CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.3 H.sub.7n                                                                             4(5) CH.sub.3                                                                  (4 or 5)                                         CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     C.sub.3 H.sub.7n                                                                             4(5) CH.sub.3                                                                  (4 and 5)                                        CH.sub.3                                                                               CH(CH.sub.3).sub.2                                                                     CH(CH.sub.3).sub.2                                                                           4(5) CH.sub.3                                    __________________________________________________________________________

EXAMPLE 3 Preparation of 1,1-Dimethylallyl o-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoate hydrochloride. ##STR28##

To a solution containing 164 mg. 1,1-dimethylallyl o-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoate (0.5 mmol) in 5 ml methylene chloride and 5 ml absolute ethanol is added 0.5 ml. 1.0 N hydrochloric acid. The mixture is concentrated in vacuo and the residue treated with ether to give a crystalline product which is removed by filtration, washed with ether and air dried to give 170 mg hydrochloride salt, melting point 259°-262° C. (decomp.). The melting point of this and other salts is dependent upon the rate of heating.

EXAMPLE 4 Preparation of o-(5-Isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid. ##STR29##

To a stirred solution containing 5 g of 3-isopropyl-3-methyl-5H-imidazo[2,1-a]isoindole-2(3H),5-dione in 15 ml dioxane is added a mixture of 10 ml concentrated hydrochloric and 10 ml water. The mixture is heated to the boiling point and then allowed to cool to room temperature. The crystalline solid is removed by filtration, washed with water, acetone and air dried. The filtrate is concentrated in vacuo, the solid washed with acetone and air-dried. Thus, in two crops, a total of 4.5 g of the lactone hydrochloride, represented by structure A, is obtained, melting point 265° C. (decomp.).

To a stirred, partial solution of the hydrochloride salt (4.5 g) in 30 ml water is added a solution containing 0.6 sodium hydroxide in 10 ml water. Complete solution occurs in a few minutes, and after approximately 15 minutes a solid separates from the solution. This is removed by filtration. The filtrate is concentrated in vacuo, the solid removed by filtration, combined with the first solid, washed with water and air-dried to give 3.8 g of o-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, melting point 162°-163° C. The analytically pure sample had melting point 163°-165° C.

EXAMPLE 5 Salts of o-(5-Isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid.

The sodium salt is prepared by adding with stirring 9.9 ml 1 N sodium hydroxide to a partial solution of 2.58 g imidazolinyl acid in 10 ml water. After 1.5 hours, the solution is concentrated in vacuo and the remaining water then removed azeotropically with dioxane to give the hydroscopic sodium salt, melting point 184°-188° C.

Amine salts are simply made in methanol. Thus, to a stirred, partial solution of 5.0 g imidazolinyl acid in 15 ml methanol is added 3.17 ml triethylamine. After 0.75 hour, a clear solution is obtained. The solution is concentrated and the residual slurry diluted with hexane, filtered and dried to give the triethylamine salt, melting point 54°-55° C. The isopropylamine salt prepared similarly has melting point 92°-98° C.

EXAMPLE 6 Postemergence Herbicidal Activity.

The postemergence herbicidal activity of the compounds of the invention is demonstrated by the following tests, wherein a variety of monocotyledonous, cyperaceous and dicotyledonous plants are treated with test compounds dispersed in aqueous acetone mixtures. In the tests, seedling plants are grown in separate cups for about 2 weeks. The test compounds are dispersed in 50/50 acetone/water mixtures containing 0.5% TWEEN® 20, a polyoxyethylene sorbitan monolaurate surfactant of Atlas Chemical Industries, in sufficient quantity to provide the equivalent of about 0.07 kg to 11.2 kg per hectare of active compound when applied to the plants through a spray nozzle operating at 2.8 kg/Cu² pressure for a predetermined time. After spraying, the plants are placed on greenhouse benches and are cared for in the usual manner, commensurate with conventional greenhouse practices. Two weeks after treatment, the seedling plants, with the exception of wild oats which are rated at 5 weeks, are examined and rated according to the rating system provided below. The data obtained are reported in Table I below.

    ______________________________________                                                            % Difference in Growth                                      Rating System:     from the Check*                                             ______________________________________                                         0 -- No effect     0                                                           1 -- Possible effect                                                                               1-10                                                       2 -- Slight effect 11-25                                                       3 -- Moderate effect                                                                              26-40                                                       5 -- Definite injury                                                                              41-60                                                       6 -- Herbicidal effect                                                                            61-75                                                       7 -- Good herbicidal effect                                                                       76-90                                                       8 -- Approching complete kill                                                                     91-99                                                       9 -- Complete kill 100                                                         4 -- Abnormal growth; that is, a definite physiological                        malformation but with an over-all effect less than                             a 5 on the rating scale.                                                       ______________________________________                                          *Based on visual determination of stand, size, vigor, chlorosis, growth        malformation and overall plant appearance.                               

Plant abbreviations:

PN--Purple Nutsedge (Cyperus rotundus L.)

SE--Sesbania (Sesbania exaltata)

MU--Mustard (Brassica kaber)

PI--Pigweed (Amaranthus retroflexus)

RW--Ragweed (Ambrosia artemisiifolia)

MG--Morningglory (Ipomoea purpurea)

BA--Barnyardgrass (Echinochloa crusgalli)

CR--Crabgrass (Digitaria sanguinalis)

FO--Green Foxtail (Setaria viridis)

WO--Wild Oats (Avena fatua)

TW--Teaweed (Sida spinosa)

VL--Velvetleaf (Abutilon theophrasti)

CN--Corn (Zea mays)

CO--Cotton (Gossypium hirsutum)

SY--Soybean (Glycine max)

RI--Rice (Oryza sativa)

JW--Jimsonweed (Datura stramonium L.)

    TABLE I       Postemergence Herbicidal Activity for Compounds having the Structure:       ##STR30##        Rate  Structure kg per Plant Species R.sub.1 R.sub.2 R.sub.3 X Hectare P      N SE MU PI RW MG TW VL BA CR FO WO CN CO SY RI        CH.sub.3 CH(CH.sub.3).sub.2 CHCCH H 11.2 3 8 8 8 5 8 8 9 7 7 6 9 -- --      -- --      4.48 7 9 9 9 5 9 9 9 3 3 8 9 7 9 9 7      1.12 3 7 9 9 2 9 7      8 3 3 3 6 7 9 9 5      0.56 1 3 9 9 2 8 3 7 0 0 0 5 7 9 9 8      0.25 3      0 9 9 3 7 5 6 5 -- 6 7 9 9 7 -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2      CH.sub.2 CH.sub.3 H 11.2 0 0 5 5 0 2 3 5 0 0 0 0 -- -- -- --      4.48      -- 9 7 8 0 4 2 1 0 1 1 -- 0 9 2 0      1.12 -- 3 3 8 0 3 0 0 0 0 0 -- 0      8 1 0       0.56 -- 0 1 6 0 2 0 0 0 0 0 -- 0 81 0 CH.sub.3 CH(CH.sub.3).sub.2       ##STR31##       H 11.24.481.120.56 0 ------ 1790 7888 7888 0100 2777 5721 7221 0100      4200 4200 4------ 2000 8997 533-- 1100 CH.sub.3 CH(CH.sub.3).sub.2      (CH.sub.2).sub.7 CH.sub.3 H 11.2 0 7 5 7 0 0 4 4 0 4 4 0 -- -- -- --      CH.sub.3 CH(CH.sub.3).sub.2 (CH.sub.2).sub.11 CH.sub.3 H 11.2 0 5 3 7 0      0 1 1 0 1 1 0 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2       CHCH.sub.2 H 11.2 0 1 7 8 0 2 5 7 0 4 4 4 -- -- -- --      4.48 -- 3 9      8 0 8 8 7 -- 0 5 -- 6 9 6 2      1.12 -- 2 9 8 0 7 2 2 0 0 0 -- 2 8 6 0          0.56 -- 0 8 8 0 7 0 2 0 0 0 -- 1 8 6 0 CH.sub.3 CH(CH.sub.3).sub.2      CH.sub.3 H 11.2 1 8 8 8 0 6 6 7 7 7 7 6 -- -- -- --      4.48 7 9 9 9 2      8 6 9 7 2 8 9 9 9 9 0      1.12 8 6 9 9 1 8 5 4 3 0 2 9 8 7 9 0      0.56 6 0 9 9 0 7 3 4 0 0 0 9 9 7 9 0 CH.sub.3 CH(CH.sub.3).sub.2      C(CH.sub.3)CHCH.sub.2 H  1.12 8 9 9 9 6 9 6 9 7 9 9 8 9 9 9 5      0.56      7 3 9 9 7 9 7 9 7 6 7 9 9 9 9 3      0.28 5 0 9 9 6 9 6 9 5 3 8 9 9 8 8      2 CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CCH H  4.48 2 0 9 9 4 9      2 2 1 1 1 8 7 8 7 0       1.12 2 0 9 9 3 8 1 2 0 1 1 6 7 7 7 --      0.56 2 0 8 9 2 8 0 2 0 0 2 0 7 7 6 -- CH.sub.3 CH(CH.sub.3).sub.2      CH(CH.sub.3).sub.2 H 11.2* 3.5 2.5 4 8.5 1.5 6 5.5 4 3.5 4.5 4.5 4 --      -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.3 H 11.2 0 0 0 9 0      4 0 0 0 0 0 0 -- -- -- --CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CH.sub.3 H      11.2 0 1 8 8 0 3 3 5 0 0 1 9 -- -- -- -- CH.sub.3 CH.sub.2 CH.sub.2      CH.sub.3 C(CH.sub.3).sub.2 CHCH.sub.2 H 11.2 2 8 3 3 0 0 0 0 0 0 0 0 --      -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CHCH.sub.2 H 11.2      9 9 9 9 9 9 9 9 9 9 9 9 -- -- -- --   HCl salt  4.48 9 9 9 9 8 9 8 9 9 9      9 9 9 9 9 8      1.12 9 9 9 9 7 9 3 9 9 9 9 9 9 9 9 8      0.56 8 7 9 9      6 9 1 9 7 5 8 9 9 9 9 7      0.28 2 3 9 9 8 9 1 5 3 5 5 5 9 9 7 7      CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CCH H 11.2 7 7 9 9 9 9 8 9      8 9 9 9 -- -- -- --   HCl salt   4.48 3 9 9 9 7 9 9 9 3 2 6 9 9 9 8 6        1.12 2 2 9 9 5 8 1 5 2 0 5 6 9 8 8 6      0.56 2 2 9 9 0 9 0 8 0 0 3 3      9 8 8 -- CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub.3)CCH H 11.2 7 9 9 9 7 9      7 9 7 7 6 9 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub. 2 CH.sub.2C(Cl)CH.sub.      2 H 11.2 9 9 9 9 9 9 8 9 9 9 9 9 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 C      H.sub.2 CH.sub.2 CCH H 11.2 6 -- 4 8 0 5 4 7 4 4 4 9 -- -- -- --      CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub.3)CHCH.sub.2 H 11.2 0 3 7 7 0 3 4      4 2 2 2 0 -- -- -- -- (CH.sub.2).sub.5 C(CH.sub.3).sub.2 CHCH.sub.2 H      11.2 0 2 6 6 4 4 4 4 4 4 4 4 -- -- -- -- CH(CH.sub.3)CH.sub.2 CH.sub.2      CH.sub.2 CH.sub.2 CH.sub.2 CCH H 11.2 0 0 4 0 0 4 0 0 8 6 3 5 -- -- --      -- CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub.3)C(CH.sub.3)CH.sub.2 H 11.2 5      9 7 7 4 4 4 4 0 0 1 0 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2   C      CHHCH.sub.3 H 11.2 2 5 6 6 0 6 3 5 5 3 2 2 -- -- -- -- CH.sub.3 CH(CH.sub      .3).sub.2 CH.sub.2 C(CH.sub.3)CH.sub.2 H 11.2 0 0 7 8 0 0 1 3 0 0 0 0 --      -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CHC(CH.sub.3).sub.2 H 11.2      3 5 7 7 0 6 5 6 2 5 3 3 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2       ##STR32##       H 11.2 0 0 3 7 0 5 2 3 0 0 0 0 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2      CH(CHCH.sub.2).sub.2 H11.2 3 9 8 9 4 9 9 9 7 8 8 7 -- -- -- -- CH.sub.3      CH(CH.sub.3).sub.2 CH(CH.sub.3)CHCHCH.sub.3 H 11.2 3 7 9 9 2 8 7 9 6 5 7      5 -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 C(CH.sub.3).sub.2 H      11.2 5 0 6 9 0 7 5 4 0 0 0 0 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2      CH.sub.2 OCH.sub.3 H 11.2 2 0 9 9 7 0 6 8 4 0 4 8      2.24 0    0 5 6 7      0 0 0 1 6 8 8      1.12 0    0 5 3 8 0 0 0 0 0 5 5      0.56 0    0 3 0      8 0 0 0 0 0 2 3       0.28 0    0 3 0 0 0 0 0 0 0 2 1 CH.sub.3 CH(CH.sub.3).sub.2       ##STR33##       H 11.22.241.120.560.28 8.5*8873 8 9 9 6*7832 99986 89987 99999 97632    0     0      953 99760 99972 7877 8988 9998 CH.sub.3 CH(CH.sub.3).sub.2 C.sub.6      H.sub.13n H 11.2 2 0 3 9 0 5 4 4 0 0 0 1 CH.sub.3 CH(CH.sub.3).sub.2       ##STR34##       H 11.22.241.12 6*32 0 9 9 000 732 620 690 200 000 000 800 CH.sub.3      CH(CH.sub.3).sub.2 CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5 H 11.2 0 0 7 9 0 4      5 6 4 0 0 4      2.24 2    2 7 8 9 2 0 0 0 5 7 8      1.12 1    0 7 5 3      0 0 0 0 2 7 3       0.56 0    0 2 2 2 0 0 0 0 0 6 5 CH.sub.3 CH(CH.sub.3).sub.2       ##STR35##       H 11.22.24 1.120.56 4.5*878 7.5* 7.5* 8.5* 2322 5*765 8.5*722 9997 5720 5     2       6730 8.5*620 776 888 887 CH.sub.3 CH(CH.sub.3).sub.2       ##STR36##       H 11.2 4.5* 4 6.5* 8* 3* 5.5* 6* 6.5* 4 0 0 5.5* CH.sub.3 CH(CH.sub.3).s      ub.2 CH.sub.2CCCH.sub.3 H 11.2 4.5* 6.5* 8.5* 9 7.5* 7.5* 8.5* 8.5* 7*      6.5* 8.5* 8.5*      2.24 7    3 8 8 9 2 0 3 8 9 8 9      1.12 3    0 8 5      9 0 0 0 2 8 8 9       0.56 3    0 7 5 9 0 0 0 0 7 8 9 CH.sub.3 CH(CH.sub.3).sub.2       ##STR37##       H 11.22.241.120.56 6.5*875 3 9 9 5000 7.5*665 7000 8.5*800 4000 4000    0      700 8*200 877 888 837 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCC.sub.7      H.sub.15n H 11.2 3 6 8 9 3 6 7 9 3 0 8 5      2.24 0    0 6 2 6 0 0 0 2      3 7 7      1.12 0    0 5 0 7 0 0 0 0 3 5 5      0.56 0    0 3 0 6 0 0 0      0 3 5 5 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CCl.sub.3 H 11.2 2 9 8 9 6      3 8 8 5 8 8 9      2.24 6    9 9 9 9 9 7 9 9 9 9 9      1.12 6    8 9 8      9 7 5 9 9 9 8 8      0.56 3    3 8 5 8 3 0 8 9 9 8 9      0.28 2    3 7      3 8 0 0 7 9 9 7 9       0.14 0    1 6 3 9 0 0 7 9 9 7 8 CH.sub.3 CH(CH.sub.3).sub.2 C(C.sub.2      H.sub.5).sub.2 CHCH.sub.2 H 11.2 1 8 7 9 5 0 6 8 5 3 7 7      2.24 7      5 8 6 9 2 2 5 7 9 7 8      1.12 1    3 7 3 9 0 0 2 6 9 7 8      0.56 1       0 8 5 9 0 0 0 3 9 6 8 CH.sub.3 CH(CH.sub.3).sub.2       ##STR38##       H 11.22.241.12 000 5 9 9 600 652 630 300 200 900 500 000 73 00 53      CH.sub.3 CH(CH.sub.3).sub.2       ##STR39##       H 11.2 0 0 8 9 0 6 0 3 0 0 0 0 CH.sub.3 CH(CH.sub.3).sub.2       ##STR40##       4(5)CH.sub.3 11.22.241.120.560.28 20000 7 9 9 88733 76320 95530 99987   2     0      86 85000 8761099999 9973 3222 7765 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.3      4(5)CH.sub.3 11.2 2 7 9 3 7 7 8 9 8 2 8 8      2.24 0    2 2 3 8 0 0 2 2      3 3 8      1.12 0    0 0 2 7 0 0 0 0 3 2 7 CH.sub.3 CH(CH.sub.3).sub.2      CH.sub.2CCH 4(5)CH.sub.3 11.2 3 8 9 9 8 7 8 9 8 9 9 9      2.24 3    9 7      5 9 8 6 8 9 9 5 9      1.12 0    9 3 5 9 2 2 6 9 9 5 7      0.56 0    3      3 3 9 2 0 6 9 9 5 7      0.28 0    3 0 0 8 0 0 3 9 9 2 6      0.14 0      2 0 0 6 0 0 0 9 7 0 5 CH.sub.3 CH(CH.sub.3).sub.2       ##STR41##       H 11.22.241.12 230 7 9 9 610 755 720 820 750 200 700 720 99 55 77      CH.sub.3 CH(CH.sub.3).sub.2 C.sub.2 H.sub.5 H 11.2 2 3 9 9 6 7 8 9 6 0 7      9  (+) isomer    2.24 7    3 6 8 9 0 0 2 9 9 7 8      1.12 6    2 6 7 9      0 0 0 9 9 8 8      0.56 5    2 6 5 9 0 0 0 9 8 8 8      0.28 3    2 5 3      9 0 0 0 3 8 6 7 CH.sub.3 CH(CH.sub.3).sub.2  CH.sub.2CCH H 11.2 3 9 9 9      9 8 9 9 7 9 9 9  (-) isomer    2.24 8    9 9 9 9 8 7 9 9 9 9 9      1.12      8    8 9 7 9 8 7 9 9 9 9 9      0.56 8    8 9 5 9 8 2 9 9 9 8 9      0.28 7    7 9 5 9 6 2 5 9 9 9 8      0.14 7    7 8 2 9 5 0 5 9 9 8 8       0.07 5    2 5 2 9 3 0 2 9 9 7 8 CH.sub.3 CH(CH.sub.3).sub.2(+) isomer       ##STR42##       H 11.22.241.120.560.280.14 2776 65 9 9 9 988830 999988 999653 999995    5     3      976 930000 999752 999993 99998 99988 99897 CH.sub.3 CH(CH.sub.3).sub.2      CH(CH.sub.3)CHCHCH.sub.3 4(5)CH.sub.3 11.2 2 8 9 9 7 6 8 9 8 7 8 7      2.24 6    7 3 7 8 0 0 3 9 9 6 8      1.12 5    6 2 5 6 0 0 4 8 7 5 7       0.56 3    5 0 3 6 0 0 0 9 7 2 6      0.28 2    2 0 2 3 0 0 0 2 3 3 3      CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.3 3(6)Cl 11.2 1 0 8 9 7 6 5 5 0 0 0 0      CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCH 3(6)Cl 11.2 0 0 9 9 6 7 8 9 0 0      0 0      2.24 0    0 5 3 0 0 0 2 0 3 6 2      1.12 0    0 5 2 0 0 0 0 0      0 6 0 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCCH.sub.2 OH H 11.2 3 8 9 9 9      9 9 9 9 9 9 9      2.24 8    8 9 9 9 9 5 9 9 9 8 8      1.12 7    6 9 6      9 6 3 7 9 9 8 8      0.56 7    3 8 6 9 2 0 6 5 9 8 8      0.28 6    3 8      6 9 2 0 3 5 9 8 8 CH.sub.3 CH(CH.sub.3).sub.2       ##STR43##       3(6)Cl 11.2 0 0 7 8 0 0 5 5 0 0 0 0 CH.sub.3 CH(CH.sub.3).sub.2      CH(CH.sub.3)CHCHCH.sub.3 3(6)Cl 11.2 0 0 6 7 0 0 0 3 0 0 0 0 CH.sub.3      CH(CH.sub.3).sub.2 C.sub.2 H.sub.5 3(6)NO.sub.2 11.2 0 0 7 9 5 4 6 5 3 7      1 0      2.24 0    0 0 3 0 3 0 0 2 0 3 0      1.12 0    0 0 0 0 0 0 0 0      0 2 0 CH.sub.3 C.sub.2 H.sub.5 CH.sub.3 H 11.2 3 0 9 9 0 6 7 9 3 3 7 7         2.24 3    0 7 8 9 0 0 0 3 3 3 7      1.12 2    0 6 8 9 0 0 0 2 0 3 7      CH.sub.3 C.sub.2 H.sub.5 CH.sub.2CCH H 11.2 3 6 9 9 7 6 7 9 7 7 9 9      2.24 5    3 7 8 9 8 0 7 9 9 7 8      1.12 5    2 7 7 9 6 0 7 7 8 6 8       0.56 3    2 5 7 9 5 0 7 2 8 5 7      0.28 2    0 3 6 8 0 0 3 0 7 5 7      CH.sub.3 C.sub.2       H.sub.5      ##STR44##       H 11.22.241.120.56 0.28 53210 7 9 9 40000 48777 75500 97620 77530 50000 8     6       76000 9877 8765 8776 CH.sub.3 CH(CH.sub.3).sub.2       ##STR45##       H 11.22.241.120.560.28 38888 8 9 9 99880 79999 89975 998 99 78855 88200 8     9       89995 9999 9998 9999 CH.sub.3 C.sub.2 H.sub.5 CH(CH.sub.3)CHCHCH.sub.3      H 11.2 2 2 9 8 5 7 7 8 7 5 6 7      2.24 3    0 8 5 7 5 0 2 0 8 7 7      1.12 3    0 6 2 5 5 0 0 0 7 6 5      0.56 1    0 5 1 5 3 0 0 0 7 7 3      CH.sub.3 CH(CH.sub.3).sub.2       ##STR46##       3(6)NO.sub.2 1 1.22.241.12 000 0 9 9 322 350 720 420 230 00 0 00 0 000  0      0 73 00 CH.sub.3 CH(CH.sub.3).sub.2       ##STR47##       H 11.22.241.120.560.280.140.07 5999833 8 9 9 9988200 7999990 8999550    9     9      999 799977 0 9983000 8998500 9999730 999987 999735 999875 CH.sub.3      C.sub.2       H.sub.5      ##STR48##        11.22.241.120.560.280.14 499822 4 8 8 200000 499986 477331 499999      3      49997 43200 0 498753 477330 999 76 77732 99887 CH.sub.3 CH(CH.sub.3).sub.      2 H 4(5)Cl 11.2 1 3 6 8 5 4 8 9 4 4 4 4   2.24 9  9 8 8 9 8 9 9 9 9 9 9       1.12 5    8 9 8 9 8 9 9 9 9 9 9   0.56 5    8 8 9 9 7 9 9 9 9 9 9      0.28 5  8 6 7 9 7 8 9 9 9 6 9   0.14 5  6 6 8 9 6 6 8 8 6 9 9   0.07 0      6 5 7 8 5 5 6 9 3 9 5 CH.sub.3 CH(CH.sub.3).sub.2       ##STR49##       H 11.22.241.120.560.28 06553 6 9 9 32100 09999 78765 99987 47533 77300  3     3      4 78933 9983 9997 9995 CH.sub.3 CH(CH.sub.3).sub.2 C.sub.2 H.sub.5      4(5)Cl 11.2 0 0 9 9 7 2 7 7 4 1 2 7   2.24 0  6 7 5 5 0 0 0 2 0 7 5      1.12 0  1 6 1 3 0 0 0 0 0 3 3 C.sub.2 H.sub.5 CH(CH.sub.3).sub.2      CH.sub.3 H 11.2 0 0 6 8 0 0 5 5 0 0 0 0 C.sub.2       H.sub.5 CH(CH.sub.3).sub.2 CH.sub.2CCH H 11.2 0 0 8 8 0 2 5 7 0 0 0 0      C.sub.2       H.sub.5 CH(CH.sub.3).sub.2      ##STR50##       H 11.2 0 0 8 8 0 1 7 7 0 0 0 0 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCH      4(5)Cl 11.2 0 0 7 8 3 0 5 5 4 1 4 4 CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub      .3)CHCHCH.sub.3 4(5)Cl 11.2 2 6 8 8 4 4 7 9 7 4 4 4   2.24 3  2 9 5 8 5      0 2 7 6 6 7   1.12 3  2 6 6 6 5 0 2 2 5 5 7   0.56 3  2 6 5 5 5 0 0 0 0      5 5 CH.sub.3 C.sub.2 H.sub.5 H H 11.2 3 8 8 8 0 5 7 9 7 4 7 7 C.sub.2      H.sub.5 CH(CH.sub.3).sub.2 H H 11.2 2 3 7 0 1 5 7 8 6 2 4 4   2.24 5  2      9 8 9 7 7 7 9 8 8 8   1.12 3  2 9 8 9 7 5 7 8 9 8 6   0.56 3  0 9 3 9 6      0 5 6 8 7 5 CH.sub.3 CH(CH.sub.3).sub.2 H 3(6)Cl 11.2 3  7 9 7 6 7 8 6 2      4 7 CH.sub.3 CH(CH.sub.3).sub.2       ##STR51##       4(5)Cl 11.2 2 7 8 9 7 7 7 8 6 5 7 5 CH.sub.3 CH(CH.sub.3).sub.2       ##STR52##       H 11.2 7 8 8 9 6 8 7 9 7 8 8 7 CH.sub.3 CH(CH.sub.3).sub.2       ##STR53##       4(5)Cl 11.2 4 7 8 7 6 6 6 9 7 3 7 9      *Average of two or more tests

EXAMPLE 7 Preemergence Herbicidal Activity

The preemergence herbicidal activity of the compounds of the present invention is exemplified by the following tests in which the seeds or propagating organs of a variety of monocotyledonous, cyperaceous and dicotyledonous plants are separately mixed with potting soil and planted on top of approximately 2.5 cu of soil in separate (size) cups. After planting, the cups are sprayed with the selected aqueous acetone solution containing test compound in sufficient quantity to provide the equivalent of about 0.28 kg to 11.2 kg per hectare of test compound per cup. The treated cups are then placed on greenhouse benches, watered and cared for in accordance with conventional greenhouse procedures. Three or four weeks after treatment, the tests are terminated and each cup is examined and rated according to the rating system set forth in Example 6. The herbicidal proficiency of the active ingredients of the present invention is evident from the test results which are reported in Table II below.

    TABLE II       Preemergence Herbicidal Activity for Compounds having the Structure:       ##STR54##        Rate  Structure kg per Plant Species R.sub.1 R.sub.2 R.sub.3 X Hectare P      N SE MU PI RW MG TW VL BA CR FO WO CN CO SY RI JW        CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CCH H 11.2 9 8 8 9 9 9 8 9 9 9 9      8 -- -- -- -- --     4.48 9 9 9 9 9 9 9 8 9 9 9 9 9 9 9 9 --     1.12* 9      7.5 9 9 5 8 8.5 8.5 9 9 9 9 8.5 9 8 9 --     0.56* 9 6.5 9 9 3 8 7.5 8.5      7.5 7 9 8.5 7.5 8 8 8.5 --     0.28 8 0 9 9 3 7 5 6 5 -- 6 7 9 9 7 -- --          0.07 9 0 8 9 0 7 5 6 6 7 7 7 5 8 7 6 -- CH.sub.3 CH(CH.sub.3).sub.2      CH.sub.2 CH.sub.2 CH.sub.3 H 11.2 9 8 9 9 9 8 8 8 7 8 9 8 -- -- -- -- --          4.48 6 8 8 9 2 8 8 8 6 7 8 8 7 9 8 6 --     1.12 3 7 8 9 0 7 7 2 0 0      0 7 3 8 5 0 --     0.56 2 7 7 9 0 4 5 1 0 0 0 4 1 7 1 0 -- CH.sub.3      CH(CH.sub.3).sub.2       ##STR55##       H 11.24.481.120.56 9981 8850 9988 9999 8500 8877 9975 9875 9850 9872    3      997 8720 --321 --971 --830 --973 -------- CH.sub.3 CH(CH.sub.3).sub.2      (CH.sub.2).sub.7 CH.sub.3 H 11.2 9 3 9 9 8 7 8 7 9 9 9 4 -- -- -- -- --         4.48 9 9 8 9 0 7 7 6 7 8 9 5 5 6 6 8 --     1.12 9 0 9 9 -- 7 2 3 5 5      8 2 2 2 3 7 --     0.56 8 0 8 9 0 7 0 2 0 2 7 0 2 0 3 3 -- CH.sub.3      CH(CH.sub.3).sub.2 (CH.sub.2).sub.11 CH.sub.3 H 11.2 9 3 8 9 0 7 7 8 8 9      9 4 -- -- -- -- --     4.48 9 5 8 9 0 7 7 7 7 8 9 4 7 6 7 8 --     1.12      9 0 8 9 0 6 3 6 3 6 8 2 2 0 2 7 --     0.56 6 0 7 9 0 2 0 2 2 2 7 0 2 0      -- 2 -- CH.sub.3 CH(CH.sub.3).sub. 2 CH.sub.2 CHCH.sub.2 H 11.2 9 8 9 9      8 8 9 9 8 9 9 8 -- -- -- -- --     4.48 9 8 8 9 8 8 8 9 9 9 9 8 8 9 9 9      --     1.12 9 7 8 9 0 8 7 7 7 7 8 7 8 8 8 7 --     0.56 9 0 8 9 0 8 2 6      5 5 7 7 7 8 7 2 -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.3 H 11.2 9 9 9 9 7      8 9 9 9 9 9 9 -- -- -- -- --     4.48 9 9 9 9 7 9 9 9 9 8 9 9 9 9 9 8 --          1.12* 7.6 3.5 9 9 2 7.6 5 8 7.5 4.5 7 8.6 7 7.6 7.6 6.5 --     0.56*      5.6 0 9 9 0 7.3 3.5 6.7 5.5 1 5 8.3 4 7.3 6.7 1.5 --     0.28 3 0 8 8 0      7 0 1 2 0 2 8 0 7 3 1 -- CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.2   C      CHH.sub.2 H 11.2 9 8 9 9 8 8 8 8 9 9 9 8 -- -- -- -- --     4.48 9 9 9 9      8 9 9 9 9 9 9 8 9 9 9 9 --     1.12 9 8 9 9 8 8 8 8 9 9 9 7 9 8 9 9 --        0.56 9 6 9 9 5 7 7 8 7 8 8 6 9 7 8 9 --     0.07 9 0 8 8 0 7 2 5 0 2 6      0 1 1 1 5 -- CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CCH H 11.2 9      8 8 9 8 8 8 8 8 9 9 8 -- -- -- -- --     0.56 8 0 8 9 0 8 5 6 6 6 7 7 5      8 5 0 -- CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub.3).sub.2 H 11.2 7 5 8 9 3      8 8 8 7 9 9 8 -- -- -- -- -- CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.      3  11.2 9 5 8 9 7 8 9 9 6 7 8 7 -- -- -- -- --     0.06 0 0 2 9 0 0 0 0      0 0 0 7 0 8 0 -- -- CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CH.sub.3 H 11.2      9 8 8 9 7 8 9 9 7 7 7 9 -- -- -- -- --     1.12 9 5 8 9 1 6 2 5 0 2 5 1      2 7 1 -- --CH.sub.3 CH.sub.2 CH.sub.2 CH.sub.3 C(CH.sub.3).sub.2      CHCH.sub.2 H 11.2 0 0 8 6 0 4 6 6 0 0 0 0 -- -- -- -- -- CH.sub.3      CH(CH.sub.3).sub.2 CH(CH.sub.3)CCH H 11.2 9 9 9 9 9 8 9 9 9 9 9 8 -- --      -- -- --     0.56 9 -- -- -- 3 8 9 8 7 7 8 8 7 9 9 -- 8CH.sub.3 CH(CH.sub      .3).sub.2 CH.sub.2 C(Cl)CH.sub.2H 11.2 9 9 9 9 8 9 8 9 9 9 9 9 -- -- --      -- --     0.14 8 -- -- -- 0 8 9 7 7 7 8 8 1 2 7 -- 7CH.sub.3 CH(CH.sub.3)      .sub.2 CH.sub.2 CH.sub.2 CCH H 11.2 9 9 9 9 8 9 9 9 9 9 9 8 -- -- -- --      --     2.24 9 -- -- -- 2 8 8 7 7 6 8 8 8 8 8 -- 9CH.sub.3 CH(CH.sub.3).su      b.2 CH(CH.sub.3)CHCH.sub.2 H 11.2 9 9 9 8 8 8 8 9 8 7 8 7 -- -- -- -- --          1.12 9 -- -- -- 0 8 9 8 7 7 8 7 7 8 5 -- 8(CH.sub.2).sub.5 C(CH.sub.3      ).sub.2       CHCH.sub.2H 11.2 9 0 8 9 0 7 9 6 6 6 6 7 -- -- -- -- -- CH(CH.sub.3)CH.s      ub.2 CH.sub.2 CH.sub.2 CH.sub.2CH.sub.2 CCHH 11.2 9 9 9 9 7 9 5 9 9 9 9      9 -- -- -- -- --    0.56 6 -- --  -- 0 2 0 0 9 9 9 9 0 0 -- -- 9   0.14      0 -- -- -- 0 0 0 0 8 9 7 0 0 0 0 -- 0CH.sub.3 CH(CH.sub.3).sub.2      CH(CH.sub.3)C(CH.sub.3)CH.sub.2 H 11.2 9 9 9 9 8 8 99 8 9 9 7 -- ---- --      --     2.24 9 -- -- -- 1 8 8 8 7 6 8 7 8 8 6 -- 8CH.sub.3 CH(CH.sub.3).su      b.2 CH.sub.2 CHCHCH.sub.3H 11.2 9 9 8 8 8 8 9 8 8 9 9 8 -- -- -- -- --       2.24 9 -- -- -- 2 8 8 8 7 7 8 8 8 9 8 -- 9CH.sub.3 CH(CH.sub.3).sub.2      CH.sub.2 C(CH.sub.3)CH.sub.2 H 11.2 9 9 9 8 8 9 9 9 8 8 9 8 -- --  -- --      --     0.56 8 -- -- -- 0 8 9 7 6 7 7 2 3 8 3 -- 9CH.sub.3 CH(CH.sub.3).su      b.2 CH.sub.2 CHC(CH.sub.3).sub.2 H 11.2 9 9 9 9 8 8 9 8 9 9 9 8 -- -- --      -- --     0.28 9 -- -- -- 0 7 9 8 8 9 9 7 9 8 9 -- 9CH.sub.3 CH(CH.sub.3)      .sub.2       ##STR56##       H 11.22.28 38 8-- 8-- 8-- 00 79 8986 7385 95 00 --1 --3 --5 ---- --9      CH.sub.3 CH(CH.sub.3).sub.2 CH(CHCH.sub. 2).sub.2 H 11.2 9 8 8 8 8 9 8 8      9 9 9 8 -- -- -- -- --     1.12 9 -- -- -- 0 8 8 8 7 7 9 3 8 8 8 -- 8      0.25 9 -- -- -- 0 7 7 6 7 6 7 0 2 8 5 -- 8    0.07 7 -- -- -- 0 2 0 0 0      3 2 0 0 0 0 -- 7CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub.3)CHCHCH.sub.3 H      11.2 9 9 8 8 8 9 8 8 9 9 9 8 -- -- -- -- --     0.56 9 0 -- -- 0 7 7 8 7      7 9 6 1 8 8 -- 8CH.sub.3 CH(CH.sub.3).sub.2       ##STR57##       H 11.22.24 89 8-- 8-- 8 --00 87 88 86 7686 87 52 --3 --8 --9---- --8      CH.sub.3 CH(CH.sub.3).sub.2C(CH.sub.3).sub.2 CHCH.sub.2 H 11.2 9 9 9 9 8      8 8 8 9 9 9 9 -- -- -- -- --    1.12 9 6 8 9 3 8 7 8 6 7 9 8 8 9 8 9 --      HCl salt  0.56 9 0 8 9 0 8 7 7 3 8 9 9 7 8 7 9 --     0.14 9 0 8 9 0 3 0      5 3 5 7 0 1 6 7 9 -- CH.sub.3 CH(CH.sub.3).sub.2 C(CH.sub.3).sub.2 CCH H      11.2 9 8 8 9 6 8 9 9 9 9 9 8 --  -- -- -- --     1.12 9 0 8 9 1 8 6 7 8      8 8 8 7 8 7 8 --   HCl salt  0.56 8 0 8 9 0 8 0 3 7 7 3 7 3 8 6 7 --      0.14 2 0 8 9 0 7 0 1 2 0 2 1 0 7 1 1 --CH.sub.3 CH(CH.sub.3).sub.2      CH.sub.2 C(CH.sub.3).sub.3 H 11.2 8 0 8 9 3 8 98 3 3 5 6  2.24 2    0 7      7 5 0 0 0 2 1 7 2 7     1.12 0    0 0 5 1 0 0 0 2 0 7 0 7 CH.sub.3      CH(CH.sub.3).sub.2 CH.sub.2 CH.sub.2 OCH.sub.3 H 11.2 9 7 9 9 3 8 8 8 8      8 9 8     2.24 5    0 8 7 3 0 0 0 6 2 7 6  9     1.12 5    0 2 0 1 0 0 0      2 1 1 2  7 CH.sub.3 CH(CH.sub.3).sub.2       ##STR58##       H 11.22.241.120.560.28 99999 8 9 9 88820 98887 99777 98887 99731 99870  9     9      9 88873 98858775 8887  9989 CH.sub.2 CH(CH.sub.3).sub.2 C.sub.6       H.sub.13n H 11.2 9 8 9 9 7 8 8 8 8 8 9 7     2.24 9    2 2 9 6 2 3 9 2      2 8 6  9     1.12 9    0 0 3 5 0 0 0 1 1 2 2  7 CH.sub.3 CH(CH.sub.3).sub      .2       ##STR59##       H 11.22.241.12 999 8 9 9 900 885 999 983 920 930 930 820 32 85 73  99      CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5 H 11.2 9      8 8 9 5 8 8 8 8 8 9 8     2.24 9    0 2 1 5 0 0 2 5 6 5 6  8     1.12 2        0 1 0 3 0 0 0 1 0 0 4  6 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2       CHCHC.sub.6 H.sub.5 H 11.2 9 9 9 9 7 8 9 9 9 9 9 8     2.24 8    0 6 6      7 1 1 9 6 3 8 5  8     1.12 6    0 3 3  0 0 0 0 0 0 3 CH.sub.3 CH(CH.sub.      3).sub.2 CH.sub.2CCC.sub.6 H.sub.5 H 11.2 9 8 9 9 8 8 8 8 9 9 9 7      2.24 9    3 8 7 6 6 6 9 3 5 2 3  8     1.12 8    0 2 2 3 2 0 5 2 0 0 0      2 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCCH.sub.3 H 11.2 9 9 9 9 9 9 9 9      9 9 9 8     2.24 9    7 8 9 9 6 8 9 9 8 8 7  9   1.12 9    2 9 9 9 5 3 8      8 8 7 7  9     0.56 9    0 3 9 9 2 0 7 2 8 7 7  8     0.28 6    0 5 7 3      0 0 0 0 3 7 5  7 CH.sub.3 CH(CH.sub.3).sub.2       ##STR60##       H 11.22.241.120.56 9999 8 9 9 9500 8863 9875 9972 9700 9700 9970 9830   1      97 877 8 65  882 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCC.sub.7 H.sub.15n      H 11.2 9 1 8 9 3 8 8 8 8 9 9 7     2.24 9    0 6 6 9 2 0 8 9 5 5 6  7       1.12 9    0 3 2 7 0 0 7 5 2 2 5  7     0.56 0    0 2 0 3 0 0 0 2 1 1 3      3 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CCl.sub.3 H 11.2 9 8 9 9 8 8 8 9      8 8 9 8     2.24 9    7 8 9 9 8 6 9 9 8 8 8  8     1.12 9    3 8 5 9 5 2      8 8 8 7 8  7     0.56 9    0 7 5 7 3 0 7 7 7 7 7  6     0.28 9    0 6 5      2 3 0 5 5 3 7 6  3 CH.sub.3 CH(CH.sub.3).sub.2 C(C.sub.2 H.sub.5).sub.2      CHCH.sub.2 H 11.2 9 9 8 9 8 9 9 9 9 8 9 8     2.24 9    5 8 9 9 7 3 7 9      9 8 8  9     1.12 9    3 8 5 7 5 0 7 9 8 7 7  8     0.56 9    0 7 0 6 0      0 3 5 7 7 7  6 CH.sub.3 CH(CH.sub.3).sub.2       ##STR61##       H 11.2 0 0 8 8 0 4 0 0 0 0 3 0 CH.sub.3 CH(CH.sub.3).sub.2       ##STR62##       H 11.2 0 0 8 9 0 7 6 7 3 5 6 3 CH.sub.3 CH(CH.sub.3).sub.2       ##STR63##       4(5)CH.sub.3 11.22.241.120.56 9975 7 9 9 8875 8852 8877 8875 9880 9850  9     8      9 8998 610 753 763  887 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.3 4(5)CH.sub.3       11.2 9 8 9 9 8 7 8 9 9 8 8 8     2.24 8*  8 7 4* 7.5* 7 7 8* 4* 5.5* 9*      8 5 7  7     1.12 6*  8 2 3.5* 3* 7 6 5.5* 0* 4.5* 9* 2 2 7  7     0.56      3.5*  8 0 0* 1*   3.5* 0* 0.5* 9* CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CCH       4(5)CH.sub.3 11.2 9 8 9 9 8 8 8 9 9 9 9 8     2.24 9    8 8 8 8 8 7 9 9          9     1.12 9    8 5 7 8 6 3 7 9     8     0.56 6    8 2 6 7 3 0 2 9         8 CH.sub.3 CH(CH.sub.3).sub.2       ##STR64##       H 11.22.241.12 999 8 9 9 800 875 865 996 983 900 952 882  7 6  76  76       88 CH.sub.3 CH(CH.sub.3).sub.2 C.sub.2 H.sub.5 H 11.2 8 6 8 9 8 8 8 9 7      6 8 8  (+) isomer   1.12 8    5 8 8 9 5 0 0 8 9 8 8  9     0.56 7    5 7      7 9 2 0 0 8 8 8 7  9     0.28 7    3 7 5 9 2 0 0 8 7 7 7  7 CH.sub.3      CH(CH.sub.3).sub.2 CH.sub.2CCH H 11.2 9 9 9 9 8 8 8 8 9 9 9 8  (-)      isomer   1.12 9    8 8 8 9 8 7 9 9 9 8 8  8     0.56 9    8 8 8 9 9 6 9      9 9 8 8  8     0.28 8    6 7 7 8 6 3 8 8 8 7 8  8     0.14 9    5 7 3 7      3 0 0 7 7 6 7  7 CH.sub.3 CH(CH.sub.3).sub.2(+) isomer       ##STR65##       H 11.22.241.120.560.280.140.07 9999963 8 9 9 8888200 8887776 8987530    8     8      989 9987530 999 5200 9998720 8888 873 998832 888863 887763  888887      CH.sub.3 CH(CH.sub.3).sub.2 CH(CH.sub.3)CHCHCH.sub.3 4(5)CH.sub.3 11.2 9      8 9 9 8 8 8 9 8 8 9 8     2.24 9    8 7 8 8 6 6 7 9 8 5 7  8     1.12 9        6 6 7 6 3 0 2 8 5 2 6  8     0.56 9    3 2 3 3 0 0 0 7 0 0 5  3      CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.3 3(6)Cl 11.2 0 0 8 9 0 7 7 7 0 0 0 0      CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CCH 3(6)Cl 11.2 7 0 8 9 6 8 8 8 0 0      0 0 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2 CCCH.sub.2 OH H 11.2 9 8 9 9 8      8 8 9 9 9 9 8     2.24 9    8 8 8 8 7 9 9 8 9 8 8  8     1.12 9    5 8 7      8 3 6 8 8 8 7 8  8     0.56 9    0 8 5 3 2 2 7 7 7 6 7  7     0.28 9      0 8 2 3 0 0 0 3 2 3 7  5 CH.sub.3 CH(CH.sub.3).sub.2       ##STR66##       3(6)Cl 11.2 0 0 9 9 0 6 7 6 0 0 0 0 CH.sub.3 CH(CH.sub.3).sub.2      CH(CH.sub.3).sub.2 CHCHCH.sub.3 3(6)Cl 11.2 0 0 8 9 0 4 7 8 0 0 0 0      CH.sub.3 CH(CH.sub.3).sub.2  C.sub.2 H.sub.5 3(6)NO.sub.2 11.2 5 0 8 8 1      8 7 7 7 7 0 2     11.2 9 5 9 8 0 8 8 9 7 0 8 9 CH.sub.3 C.sub.2 H.sub.5      CH.sub.3 H 2.24 7    0 8 8 9 3 0 3 8 5 6 7  9     1.12 2    0 7 7 8 0 0      0 7 0 3 5  8     11.2 9 8 9 9 3 8 8 9 8 8 8 9 CH.sub.3 C.sub.2 H.sub.5      CH.sub.2CCH H 2.24 9    0 8 8 9 7 6 9 8 7 7 7  9     1.12 9    0 8 6 8 3      2 3 6 3 5 6  8     0.56 3    0 7 5 5 0 0 0 0 0 2 2  8 CH.sub.3 C.sub.2      H.sub.5       ##STR67##        H 11.22.241.120.560.28 99752 7 9 9 80000 88873 98600 98210 96300 96000 9     8       88620 7310 5531 6320  8877 CH.sub.3 CH(CH.sub.3).sub.2       ##STR68##       H 11.22.241.120.560.28 99998 8 9 9 88200 8886 2 98765 99 876 99830      99520 99850 88730 8771 876 5 8877  8888 CH.sub.3 C.sub.2 H.sub.5       ##STR69##       H 11.22.241.12 99 9 6 9 9 000 887 885 982 852 720 852 830 72 75 7 5  88      CH.sub.3 CH(CH.sub.3).sub.2       ##STR70##       3(6)NO.sub.2 11.2 5 0 8 8 6 7 8 8 5 0 6 5 CH.sub.3 CH(CH.sub.3).sub.2       ##STR71##       H 11.22.241.120.560.280.14 999 899 7 9 9 880000 788772 8 87350 997831   3     0      89 987000 899880 886530 98766 87532  86521  88883 CH.sub.3 C.sub.2      H.sub.5       ##STR72##       H 11.22.241.120.56 9997 0 8 8 0000 8875 8873 8971 7720 8510 8960 8520   1      85 862 875  880 CH.sub.3 CH(CH.sub.3).sub.2       ##STR73##       H 11.22.241.120.56 973 0 9 8 9 8000 8763 8865 988 8653 8760 8876 7300   0      30 531 521  987     11.2 8 1 8 9 8 8 7 9 6 3 7 7 CH.sub.3 CH(CH.sub.3).su      b.2 C.sub.2 H.sub.5 4(5)Cl 2.24     2 7 5 6 3 1 3 8 0 6 3     1.12 1      0 5 5 2 0 0 1 8 0 3 0 C.sub.2 H.sub.5 CH(CH.sub.3).sub.2 CH.sub.3 H 11.2      3 0 8 8 0 6 3 6 1 1 1 1 C.sub.2 H.sub.5 CH(CH.sub.3).sub.2 CH.sub.2C CH      H 11.2 7 0 8 9 0 8 8 8 7 6 8 8 C.sub.2 H.sub.5 CH(CH.sub.3).sub.2       ##STR74##       H 11.2 3 0 8 9 0 8 8 8 67 8 5     11.2 9 8 9 9 8 8 8 9 9 9 9 9     2.24      9    8 8 8 8 8 8 8 8 8 8 7  8 CH.sub.3 CH(CH.sub.3).sub.2 H4(5)Cl 1.12 9         8 8 7 8 8 8 9 8 8 8 7  8     0.56 9    6 8 7 8 6 3 8 8 7 7 7  8      0.28 9    6 7 8 7 5 3 5 6 5 5 6  8     0.14 9    0 5 3 6 3 1 2 5 3 3 5      5     11.2 9 8 8 9 8 8 8 9 8 8 9 8 CH.sub.3 CH(CH.sub.3).sub.2 CH.sub.2CC      H 4(5)Cl 2.24 8    8 8 7  8 8 7 8 6 8 5  8     1.12 6    7 8 5  7 7 7 8      1 0 5  8     0.56 5    7 8 2  5 5 6 7 0 1 1 8     0.28 3    7 7 0  2 0 3      7 0 0 1  8 CH.sub.3 CH(CH.sub.3).sub.2       ##STR75##       4(5)Cl 11.2 2.24 1.12 0.56 9962 8 8 8 8870 8735 8200 86 87 76 8700 8752 8     7       620 510 653  7 30    11.2 9 8 8 8 8 8 8 8 8 8 8 8 CH.sub.3 C.sub.2      H.sub.5 H H 2.24 9    0 8 8  9 9 9 8 8 9 9  8     11.2 9    0 8 8 8 9 9      9 8 7 9 8  8     0.56 9    0 8 7  1 1 3 5 3 3 8  8     0.28 9    0 7 5      1 1 5 2 3 3 7  7     11.2 9 0 8 8 3 8 8 8 7 8 8 5 C.sub.2 H.sub.5      CH(CH.sub.3).sub.2 H H 2.24 9    0 8 2  3 2 7 0 3 6 5  7     1.12 8    0      6 0 7 0 0 3 0 3 5 2  1    0.56 9    0 3 0 0 0 0 0 0 1 2 2  0    11.2 9 8      8 8 8 8 8 8 9 8 9 8 CH.sub.3 CH(CH.sub.3).sub.2 H 3(6)Cl 2.24 9    9 8 7       8 9 8 8 9 9 8  8    1.12 9    8 8 3  7 6 3 7 7 8 8  8    0.56 9    7 8      2  3 1 1 2 6 8 8  7     0.28 9    7 8 2  1 0 0 2 2 8 7  7 CH.sub.3      CH(CH.sub.3).sub.2       ##STR76##       4(5)Cl 11.2 2.24 1.12 0.56 0.28 0.13 999850 8 8 9 887 888773 8 75100    5     0      9760 898750 898853 887653 888520 72000 85633 75221 88887 CH.sub.3      CH(CH.sub.3).sub.2       ##STR77##       H 11.2 2.24 1.12 0.56 0.28 0.14 0.07 999999 9 9 8 8 888 8888775 8888755 8      988776 9999777 8998888 9998776 8888653 977522 888887 877762  888887      CH.sub.3 CH(CH.sub.3).sub.2       ##STR78##       4(5)Cl 11.22.241.120.560.28 99988 7 8 8 80 88887 88551 88531 8 8770     1      8887 88765 88620 8332 8985 8776  8875      *=AVERAGE OF TWO OR MORE TESTS.

EXAMPLE 8 Selective Postemergence Herbicidal Activity

The selective postemergence herbicidal activity of the compounds of the invention is demonstrated by the following tests, wherein sorghum [Sorghum bicolor (L) Woeuch], spring wheat (Triticum acstivum, cv. Auza) and barley (Hordcum vulgare, cv. Steptoe) plants are treated with test compounds dispersed in aqueous acetone mixtures. In these tests, the procedure described in Example 6 is followed, and the treated plants are examined and rated according to the rating system set forth in Example 6.

The data obtained are reported in Table III below.

                                      TABLE III                                    __________________________________________________________________________     SELECTIVE POSTEMERGENCE HERBICIDAL ACTIVITY                                    OF COMPOUNDS HAVING THE STRUCTURE:                                              ##STR79##                                                                                                   Rate                                             STRUCTURE                     kg per                                                                              PLANT SPECIES                               R.sub.1                                                                            R.sub.2                                                                               R.sub.3       X    Hectare                                                                              Sorghum                                                                            Auza                                                                              Steptoe                             __________________________________________________________________________                                   2.24 2    5  2                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2 CH.sub.2 OCH.sub.3                                                                  H    1.12 0    5  0                                                                 0.56 0    0  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR80##    H    2.24 1.12 0.56                                                                      2 0 0                                                                               5 3 5                                                                             0 0 0                               CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5                                                           H    2.24 3    2  2                                                                 1.12 0    2  2                                                                 0.56 0    0  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR81##    H    2.24 1.12 0.56                                                                      3 0 0                                                                               6 5 3                                                                             3 0 0                               CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2CCC.sub.7 H.sub.15n                                                                  H    2.24 2    3  0                                                                 1.12 0    2  0                                                                 0.56 0    2  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR82##    H    2.24 1.12 0.56                                                                      0 0 0                                                                               3 0 0                                                                             2 0 0                                                             2.24 2    1  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.3      4(5)CH.sub.3                                                                        1.12 2    0  0                                                                 0.56 0    0  0                                        CH(CH.sub.3).sub.2                                                                   C.sub.2 H.sub.5                                                                              H    2.24 2    9  2                                   CH.sub.3                                                                           (+) isomer                1.12 1    8  0                                                                 0.56 0    3  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2CCH   3(6)Cl                                                                              2.24 2    0  0                                                                 1.12 0    0  0                                                                 0.56 0    0  0                                                                 2.24 0    0  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    C.sub.2 H.sub.5                                                                              3(6)NO.sub.2                                                                        1.12 0    0  0                                                                 0.56 0    0  0                                                                 2.24 0    2  0                                   CH.sub.3                                                                           C.sub.2 H.sub.5                                                                       CH.sub.3      H    1.12 0    3  0                                                                 0.56 0    0  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR83##    3(6)NO.sub.2                                                                        2.24 1.12 0.56                                                                      0 0 0                                                                               0 0 0                                                                             6 7 1                                                             2.24 0    0  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    C.sub.2 H.sub.5                                                                              4(5)Cl                                                                              1.12 0    0  0                                                                 0.56 0    0  0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR84##    4(5)Cl                                                                              2.24 1.12 0.56                                                                      6 3 0                                                                               0 0 0                                                                             0 0 0                               __________________________________________________________________________

EXAMPLE 9 Selective Preemergence Herbicidal Activity.

By the procedure described in Example 7, the selective preemergence herbicidal activity of the compounds of the invention is evaluated using sorghum [Sorghum bicolor (L) Moeuch], spring wheat (Triticum acstivum, cv. Auza) and barley (Hordeum vulgare, cv. Steptoe). At termination the tests are rated according to the rating system set forth in Example 6.

The data obtained are reported in Table IV below.

                                      TABLE IV                                     __________________________________________________________________________     SELECTIVE PREEMERGENCE HERBICIDAL ACTIVITY OF                                  COMPOUNDS HAVING THE STRUCTURE                                                  ##STR85##                                                                                                 Rate                                               STRUCTURE                   kg per                                                                              PLANT SPECIES                                 R.sub.1                                                                            R.sub.2                                                                                R.sub.3    X    Hectare                                                                             Sorghum                                                                             Auza Steptoe                             __________________________________________________________________________     CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2 C(CH.sub.3).sub.3                                                                 H    2.24 0    2    0                                                               1.12 0    0    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2 CH.sub.2 OCH.sub.3                                                                H    2.24 0    7    2                                                               1.12 0    3    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    C.sub.6 H.sub.13n                                                                          H    2.24 3    2    0                                                               1.12 0    0    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR86##  H    2.24 1.12 0.56                                                                      2 0 0                                                                               5 3 0                                                                               2 0 0                               CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2 CH.sub.2 OC.sub.2 H.sub.5                                                         H    2.24 2    8    7                                                               1.12 0    5    0                                                               0.56 0    3    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2 CHCHC.sub.6 H.sub.5                                                               H    2.24 3    7    3                                                               1.12 2    0    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.3    4(5)CH.sub.3                                                                        2.24 8    2    3                                                               1.12 8    0    0                                                               0.56 2    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    CH.sub.2CH.sub.2                                                                           H    2.24 0    6    3                                                               1.12 0    0    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           C.sub.2 H.sub.5                                                                       CH.sub.3    H    2.24 2    2    2                                                               1.12 0    0    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                    C.sub.2 H.sub.5                                                                            4(5)Cl                                                                              2.24 0    7    0                                                               1.12 0    0    0                                                               0.56 0    0    0                                   CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR87##  H    2.24 1.12 0.56                                                                      5 0 0                                                                               6 3 0                                                                               2 0 0                               CH.sub.3                                                                           CH(CH.sub.3).sub.2                                                                     ##STR88##  4(5)Cl                                                                              2.24 1.12 0.56                                                                      8 2 1                                                                               7 5 2                                                                               2 0 0                               __________________________________________________________________________ 

I claim:
 1. A method for the control of undesirable plant species comprising, applying to the foliage of the plants or to soil containing seeds, seedlings or propagating organs of the plants, a herbicidally effective amount of a compound having the structure: ##STR89## wherein X is hydrogen, alkyl C₁ -C₃, halogen or nitro; R₁ is alkyl C₁ -C₄ ; R₂ is alkyl C₁ -C₆, cycloalkyl C₃ -C₆, alkenyl C₂ -C₄, phenyl, halophenyl or benzyl or when R₁ and R₂ are taken together with the carbon to which they are attached they may represent cycloalkyl C₃ -C₆ optionally substituted with methyl; R₃ is hydrogen, alkyl C₁ -C₁₂ optionally substituted with one C₁ -C₃ alkoxy group or one C₃ -C₆ cycloalkyl group or one phenyl group or one furyl group, alkenyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s) alkynyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl group(s) or one phenyl group or with one to two halogen substituent(s), benzyl, cyclohexenylmethyl, ethynylcyclohexyl, ethynylallyl or pentadienyl, cycloalkyl C₃ -C₆ optionally substituted with one or two C₁ -C₃ alkyl group(s); or a salt-forming cation of alkali metals, ammonium or C₁ -C₁₈ aliphatic ammonium; and when R₁ and R₂ are not the same the optical isomer thereof, or an isomeric mixture thereof; or except when R₃ is a salt-forming cation, the strong acid addition salt thereof.
 2. A method according to claim 1 for the preemergence control of undesirable plant species, wherein the compound is applied at a rate of from 0.07 kg to 11.2 kg per hectare to soil containing seeds, seedlings or other propagating organs of said undesirable plants.
 3. A method according to claim 1 for the control of cyperaceous and other perennial plants, comprising applying to soil containing seeds or other propagating organs of the cyperaceous or perennial plants, from about 0.56 kg per hectare to 25 kg per hectare of the compound of claim
 1. 4. A method according to claim 1 for the postemergence control of undesirable plants, comprising, applying to the foliage of the plants from about 0.28 kg per hectare to 25 kg per hectare of a compound according to claim
 1. 5. A method according to claim 1, wherein X is hydrogen, methyl, chlorine and nitro; R₁ is alkyl C₁ -C₃ ; R₂ is alkyl C₁ -C₃ or cyclohexyl and when R₁ and R₂ are taken together with the carbon to which they are attached they represent cyclohexyl or methylcyclohexyl; R₃ is hydrogen, alkyl C₁ -C₁₂, alkenyl C₃ -C₅ optionally substituted with one or two chlorine substituents, or one or two C₁ -C₃ alkyl substituents, alkynyl C₃ -C₅ optionally substituted with one or two C₁ -C₃ alkyl substituents, benzyl, cyclohexenylmethyl or pentadienyl; and when R₁ and R₂ are not the same the optional isomer thereof, or the isomeric mixture thereof; or the acid addition salt thereof.
 6. A method according to claim 1, wherein X is hydrogen, methyl or chlorine; R₁ is methyl; R₂ is isopropyl; and R₃ is as described in claim
 1. 7. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, 2-propynyl ester.
 8. A method according to claim 1 wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, methyl ester.
 9. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid.
 10. A method according to claim 1, wherein the compound is the isomeric mixture of 6-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-m-toluic acid, methyl ester and 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-p-toluic acid, methyl ester.
 11. A method according to claim 1, wherein the compound is (+)-2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, ethyl ester.
 12. A method according to claim 1, wherein the compound is (+)-2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, 2-chloroallyl ester.
 13. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, 1,1-dimethylallyl ester.
 14. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, allyl ester.
 15. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid, octyl ester.
 16. A method according to claim 1, wherein the compound is 2-(5-ethyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid.
 17. A method according to claim 1, wherein the compound is the isomeric mixture of 3-chloro-2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid and 6-chloro-2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid.
 18. A method according to claim 1, where the compound is (-)-2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid-, 2-propynyl ester.
 19. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid-, compound with isopropylamine.
 20. A method according to claim 1, wherein the compound is an isomeric mixture of 6-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-m-toluic acid and 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-p-toluic acid.
 21. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid-, sodium salt.
 22. A method according to claim 1, wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)benzoic acid-, 1-methyl-2-butenyl ester.
 23. A method according to claim 1 for controlling wild oats in the presence of barley or wheat wherein the compound is 6-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-m-toluic acid, methyl ester.
 24. A method according to claim 1 for controlling wild oats in the presence of barley or wheat wherein the compound is 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl-p-toluic acid, methyl ester.
 25. A method according to claim 1 for controlling wild oats in the presence of barley or wheat wherein the compound is the isomeric mixture of 6-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl)-m-toluic acid, methyl ester and 2-(5-isopropyl-5-methyl-4-oxo-2-imidazolin-2-yl-p-toluic acid, methyl ester. 